The present invention relates to a new and improved inclinometer in which light barriers are used to measure and monitor an inclination relative to an artificial horizon which is determined by the mirror plane of a liquid contained in a vessel and wherein a deviation exceeding an adjustable quantity in the position of a reference plane of the inclinometer relative to the artificial horizon triggers an alarm.
An inclinometer of this kind serves, for example, to warn a vehicle driver of the danger of his or her vehicle overturning when travelling over hilly terrain. Inclinometers designed as overturning warning devices which comprise a U-shaped vessel partially filled with liquid are in fact known to the art. For example, the French application No. 74 06386 describes an overturning warning device of this type comprising two floats. Such overturning warning device responds relatively well in the event of a tilting movement in the plane which contains the U-shaped vessel, but is insufficiently accurate in the case of tilting movements in other planes.